• indium tin oxide
• ITO
• localized surface plasmon resonance
• LSPR
• nanocomposites
• nanoparticles
• Plasmonics
• smart polymeric nanocomposites
• smart polymers

Noble metals have been the most widely employed materials for plasmonics for years. However, new, less expensive and more functional materials have recently entered the world of plasmonics. These include doped semiconductors, and among these tin-doped indium oxide (ITO, Indium Tin Oxide), the subject of this thesis. It differs from noble metals for its optical transparency, accompanied by good electrical conductivity. ITO nanoparticles show a plasmon resonance peak in the near infrared and their plasmonic properties can be modulated as a function of doping.
First, the basic concepts of plasmonics are introduced. The attention is focused mainly on localized surface plasmons in nanoparticles, which are the object of study of this thesis.
The main synthetic approaches for ITO nanoparticles are presented and a new synthetic approach is proposed.
Then, ITO nanoparticles obtained in this this work are characterized. Optical and magneto-optical properties are analysed and Drude parameters (the electron effective mass and the density of free electrons) are extrapolated from the absorption and the MCD spectra.
Finally, ITO nanoparticles are dispersed in polymer matrices in order to prepare nanocomposites. Polyethylene is used to prepare smart polymeric nanocomposites responsive to mechanical stimuli, while stamps obtained with a polystyrene matrix are studied for their photothermal activity, with potential application in the field of anti-counterfeiting.